This is a note to let you know that I've just added the patch titled io_uring: Use original task for req identity in io_identity_cow() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-use-original-task-for-req-identity-in-io_identity_cow.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From lee@xxxxxxxxxx Sat Jul 23 15:54:25 2022 From: Lee Jones <lee@xxxxxxxxxx> Date: Tue, 19 Jul 2022 12:52:51 +0100 Subject: io_uring: Use original task for req identity in io_identity_cow() To: lee@xxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx, Jens Axboe <axboe@xxxxxxxxx>, Pavel Begunkov <asml.silence@xxxxxxxxx>, Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>, io-uring@xxxxxxxxxxxxxxx, linux-fsdevel@xxxxxxxxxxxxxxx Message-ID: <20220719115251.441526-1-lee@xxxxxxxxxx> From: Lee Jones <lee@xxxxxxxxxx> This issue is conceptually identical to the one fixed in 29f077d07051 ("io_uring: always use original task when preparing req identity"), so rather than reinvent the wheel, I'm shamelessly quoting the commit message from that patch - thanks Jens: "If the ring is setup with IORING_SETUP_IOPOLL and we have more than one task doing submissions on a ring, we can up in a situation where we assign the context from the current task rather than the request originator. Always use req->task rather than assume it's the same as current. No upstream patch exists for this issue, as only older kernels with the non-native workers have this problem." Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Pavel Begunkov <asml.silence@xxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: io-uring@xxxxxxxxxxxxxxx Cc: linux-fsdevel@xxxxxxxxxxxxxxx Fixes: 5c3462cfd123b ("io_uring: store io_identity in io_uring_task") Signed-off-by: Lee Jones <lee@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1325,7 +1325,7 @@ static void io_req_clean_work(struct io_ */ static bool io_identity_cow(struct io_kiocb *req) { - struct io_uring_task *tctx = current->io_uring; + struct io_uring_task *tctx = req->task->io_uring; const struct cred *creds = NULL; struct io_identity *id; Patches currently in stable-queue which might be from lee@xxxxxxxxxx are queue-5.10/io_uring-use-original-task-for-req-identity-in-io_identity_cow.patch